Tony Blair is pushing for greater cooperation between the G8 group of industrialised countries on spending the $25bn of additional aid for Africa agreed at last month's Gleneagles summit to ensure it is effectively targeted to tackle poverty.

But government officials are gloomy about a lack of progress in trade talks ahead of the World Trade Organisation meeting in Hong Kong in December, where they hope the industrialised world will agree to lift many of its agricultural subsidies to give Africa greater access to western markets.

The prime minister wants to use the UN millennium summit next month to press for clearer mechanisms to distribute the extra funds, and has set up a series of conferences to chase progress on the commitments made last month. The G8 summit agreed to increase total aid by $48bn by 2010, of which $25bn (about £14bn) extra will go to Africa, and to provide 100% multilateral debt relief to 14 of its most heavily indebted countries.

No 10 is privately hoping some non G8 countries, including Australia, will also announce further increases in overseas aid in the next few months. The UN summit communique is also expected to suggest debt relief can be extended to more countries shortly. On coordinating the spending of the extra aid, Mr Blair is hoping that the Organisation of Economic Cooperation and Development will ensure there is not any over- or undersupply of aid in specific countries or areas.

He is also looking for the World Bank to coordinate G8 spending on achieving the UN millennium development goal of universal access to healthcare. It already works to harmonise spending on the millennium goal of universal primary education.

Mr Blair has also called a meeting of the African Partnership Forum in October to discuss mechanisms for spending the extra aid in Africa and to monitor the 50 non-aid proposals agreed at the G8.

On Aids, Britain will host a conference in London next month to look at funding the G8 goal of achieving universal access to antiretroviral treatment by 2010. The UN-backed Global Fund to fight Aids, TB and Malaria, which channels donors' support to developing countries, reckons it needs another $2.5bn this year, and a further $7.1bn in the following two years.

The prime minister is also backing an idea of an airline ticket levy as a way of raising extra development aid. The French president, Jacques Chirac, has written to 145 world leaders to ask them to back the plan, capable of raising $3bn a year, at the UN summit. The tax, a surcharge on taking off from airports in participating countries, would help countries like Germany and Italy which will struggle to meet the EU goal of 0.7% of GDP.

But government officials are pessimistic about any breakthrough on trade at the WTO meeting in December.